1. Field of the Invention
The present invention relates to seals, to methods of sealing, and to apparatus having such seals. In another aspect, the present invention relates to O-ring seals, to methods of sealing, and to apparatus having such seals. In even another aspect, the present invention relates to pressurized O-ring seals, to methods of sealing, and to apparatus having such seals. In still another aspect, the present invention relates to pressurized expandable O-ring seals, to methods of sealing, and to apparatus having such seals.
2. Description of the Related Art
O-ring type seals are commonly used to form an effective seal between two mating parts. An example of an O-ring type seal includes a plug having a gland groove in which a O-type seal is placed. In order for such a plug to seal a tubular member, the O-ring must have a diameter larger than the both the inner diameter of tubular member and the outer diameter of the plug. When the plug is inserted into the tubular member, the O-ring is squeezed between the two thereby forming a seal. Typically, for such a seal to be effective, the inner diameter of the tubular member must be machined smoothed at the point of sealing.
In another example, a plug can include screw threads. The tubular member would include complimentary threads and would also normally include lead-in angles to allow an O-ring to be squeezed down when entering the sealing area of the tubular member as the plug is screwed in. To form an effective seal, the tubular member will again require machining to remove any scale or other surface roughness at the sealing area, and provide an even surface for the O-ring to seat against. A disadvantage of this type of O-ring seal is that the threaded area on the tubular member must be under-cut to avoid damage to the O-ring by the threads on the tubular member as the plug is being inserted.
In order to make an effective seal, it is therefore common practice in the prior art to have the O-ring gland groove slightly larger than the inner diameter of the O-ring and wider than the cross section of the O-ring. This design gives the squeeze to the O-ring and allows axial movement of the O-ring as it is inserted into the sealing area. A typical O-ring has a `squeeze` or reduction in its original cross section of about 10% to about 15% to form a seal.
Therefore, there is a need in the art for an O-ring seal that does not suffer from the disadvantages of the prior art, to a method of making such a seal, and to apparatus including such a seal.
Therefore, there is a need in the art for an O-ring seal that conforms to any sealing surface, to a method of making such a seal, and to apparatus including such a seal.
There is even another need in the art for an effective O-ring seal that does require expensive time consuming machining of and/or undercuts to the sealing surface, to a method of making such a seal, and to apparatus including such a seal.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.